Implantable medical device systems known in the art comprise several components, including an implantable medical device, such as a pacemaker, pacing and/or sensing leads (leads), and a programmer. The leads connect the implantable medical device to the heart of a patient. The programmer provides multiple functions, including (a) assessing lead performance during a pacemaker or defibrillator implantation, (b) programming the implantable medical device, and (c) receiving feedback information from the implantable medical device for use by a clinician or physician (operator). By measuring the electrical performance of a lead, the programmer aids the operator in selecting an electrically appropriate site for the placement of the lead(s).
In conjunction with programming the implantable medical device system, it is critical for an operator to determine whether the leads are properly positioned within a passageway of a heart, such as an atrium or ventricle of the patient.
A disadvantage of prior art programmers involves the techniques used to display information to the operator during an implant procedure. Most prior art systems graphically display several, continuous-time waveforms, which are constantly scrolling across the screen at a rapid rate. The remaining information is presented to the operator in the form of numerical data. In order to determine if a specific lead is properly positioned within a passageway of the heart, the operator must review not only the graphical display of the continuous-time cardiac waveform scrolling across the display, but also review a variety of numerical data. The operator must then have the ability and understanding to process the various data shown both graphically and numerically in order to determine if the lead is positioned to ensure proper operation of a later attached implantable medical device.
U.S. Pat. No. 5,713,937 to Nappholz et al disclsoes a pacemaker programmer menu with selectable real or simulated implant data graphics. This reference discloses a graphical display of two separate characteristics of an implantable medical device system, such as a heartbeat of a poatient and a ventricular pacing rate as applied to a medical implant.
The prior art in general, as well as the Nappholz et al reference in particular, have certain disadvantages. For example, the display units of the prior art patents employ a continuous-time cardiac waveform. This waveform is continuously scrolling across the display. Once the continuous-time waveform reaches the end of the display, the waveform disappears and a new continuous-time waveform is generated in real time and scrolls across the screen. Thus, it is virtually impossible for an operator to determine the configuration of the waveform signal, or to determine the amplitude of the signal. Additionally, the operator must evaluate various numerical data in conjunction with the graphical display to determine if a specific lead is properly positioned.